The invention concerns a device for assembly of a flexible conduit element comprising a flexible ring-corrugated or helical-shaped bellows member and a surrounding jacket cooperating therewith and having an inner arbor penetrating through the bellows member.
Devices of this type are used for the assembly of flexible conduit elements such as metallic exhaust tubes. These types of conventional conduit elements (U.S. Pat. No. 5,769,643, FR 2 685 435) primarily serve for the acceptance of vibrations to prevent their transmission from a rigid component to a neighboring component. The conduit elements thereby preferentially comprise a bellows member having a corrugated or helical structure and a jacket surrounding same made from a woven or knitted material which is captured by rings of the bellows member and which damps characteristic vibrations of the bellows member.
During conventional manufacture of an element of this type comprising a bellows body and an outer woven or knitted tube or conduit element, the latter had been displaced over the free bellows and fixed at the outside between the rings of the bellows body. The bellows body had been disposed on an inner arbor during this assembly procedure.
This procedure has the substantial disadvantage that attachment of the jacket to the bellows body is performed in an undefined fashion and substantial tolerance fluctuations in length can occur. The free disposition of the highly flexible bellows body on the inner arbor can preclude a defined cutting to length of the bellows body and essentially prevents a plane parallel cut when cutting to length.
DE 42 02 808 A1 discloses a flexible conduit element for exhaust conduits having a ring-corrugated or helical bellows and a metal tube disposed therein, the ends of which are connected with the ends of the bellows to connectors for the exhaust conduit. This product has been manufactured by initially cutting the bellows and the metallic tube to the desired length. The ends of the sectioned bellows or metal tube are provided with a support ring and the bellows and the metal tube are combined after disposition of a ring-shaped drive element on the ends. A conduit element of this kind, preassembled in this fashion, is placed in or on a magnetic coil for concentric centering of the bellows and metallic tube and, in order to bridge the separation between the bellows and the metallic tube, the metallic tube is widened against the inner wall of the outer support ring while the corrugations of the bellows are pushed together and the individual layers of the various components are pressed together and/or the corrugations of the bellows and the agraff structure of the metal tube are pressed together against the outer wall of the inner support ring or of a support arbor penetrating through the support ring. A pre-assembled conduit element is preferentially inserted into a magnetic pulse device and the differing components are pressed together by electrically conducting drive elements using the magnetic pulse procedure.
It is the underlying purpose of the invention to propose a device for the assembly of a flexible conduit element with which the above mentioned disadvantages are avoided.
This purpose is achieved in accordance with the invention in the device of the above mentioned kind in that the inner arbor has elements for engaging into the bellows body, wherein the length of the inner arbor can be adjusted. The elements of the inner arbor engaging into the bellows body thereby fix the location of the bellows body relative thereto i.e. to prevent displacement of the bellows body on the inner arbor during placement of the jacket. In addition, the inner arbor has a length which can be adjusted to thereby facilitate setting of the length of the bellows body to a predetermined preferred value.
In a preferred embodiment, the elements engage the corrugated portions of the bellows body at the ends thereof to thereby subject the individual corrugated sections to a substantially even tensile and compression forces so that the separation between the individual corrugations relative to each other remains substantially constant.
Advantageously, the elements for engagement into the end corrugations of the bellows body are pawls which engage in a positive connecting fashion into a corrugation of the bellows body with at least one outwardly projecting collar member to thereby serve as a holding or carrier element therein.
Advantageously, the pawls are borne for pivoting on the inner arbor so that they can be pivoted from an inactive position into an active position in cooperation with the spreading arbor and vice versa.
Further advantages and features of the invention can be extracted from the following description with reference to the drawing.